Recycled concrete thrives in its second life
It looks like concrete and it feels like concrete. Any why not? It used to be concrete, and now it is again. Ekocrete is a new incarnation of concrete that uses 90% recycled and by-product materials such as fly ash. “Ekocrete was designed from the ground up to use no mined aggregate and significantly less cement,” said company president Jim Glessner.
Developing the ideal mix for Ekocrete took about 18 months, according to Richard McCabe, the company's VP/Technology. “I'll tell you, to get to 90 percent recycled content and reach 5,000 psi was quite a chore,” hes aid.
The challenge was finding the right balance of recycled aggregate, fly-ash, and other recycled materials. Key additives include post-industrial recycled nano-fibers, which assist in building the concrete's flexural strength and crack reducing properties. Other recycled particles help improve the concrete's surface density to more effectively ward off water penetration.
“It's a pretty cool concrete…” said McCabe. “This product can exceed the performance of traditional concrete in compressive, tensile and flexural strength. Its longevity is expected to be many times greater than traditional concrete due to its use of nano-fibers, pozzolans, and small particles that provide high surface density.”
The compressive strength of the standard mix is 4000 psi, but a range of 2000 – 10,000 psi is also available.It can be colored, stained, stamped, and acid etched.
In developing the product, the Ekocrete team expected its primary use would be for slabs, pavement, and the like. It's being tested by a radiant flooring vendor, and the company has already been in contact with other parties interested in using Ekocrete in ICFs and other structural applications. In fact, it's been fast-tracked for structural use in a city-block sized five-story building in San Francisco.
Ekocrete is manufactured by Basalite and supplied in 50-pound sacks. The product will be distributed by Buddy Rhodes Concrete Products, and is priced competitively with conventional concrete. The new product will likely be eligible for LEED credits for recycled content.
Building Products Group / AAC
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